🚀 go-pugleaf

In article <1992Mar31.222837.332@msus1.msus.edu> schuman@msus1.msus.edu writes:

   After installing GCC2.0 on an RS-6000, I have been having some problems with
   packed data structures.  Here is the problem:

   Sample Program--
   main ()
   {
           typedef struct {
                char a[13];
                int  b;
           } c;

           printf("The size = %d", sizeof(c));
   }

   The output of the program is 20.  I want to compile the program so it will pack
   the data structure and print out 17.  If anyone knows how to make to gcc 
   compiler not allign its structures on 4 byte boundaries, it would be extremely
   helpful.

I think, there is no way of acomplishing that. Most modern processors
require an alignment to word boundaries and especially RISC processors
do so. There are good reasons for implementing such restrictions in
hardware, they make the design of the chip simpler. I can't definitely
say, that the RS6000 is such a processor but I do think so. That
means, a compiler always HAS TO use the `natural' alignment of the
architecture. What `gcc' does is therefore absolutely correct. If you
need a portable format of structures, use XDR routines for data
conversion. They are part of the Sun RPC package.
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